A DC-DC converter converts a direct current (DC) power source from one voltage level to another. A DC-DC converter may be, for example, a Buck DC-DC converter in which the input voltage is higher than the output voltage, a Boost DC-DC converter in which the input voltage is lower than the output voltage, or a Buck-Boost DC-DC converter in which the input voltage is higher or lower than the output voltage.
In a voltage regulator, such as a Buck DC-DC converter, a Boost DC-DC converter, or a Buck-Boost DC-DC converter, when the input voltage and the output voltage of the voltage regulator are close to each other, an inductor peak current can be rather small, which causes degradation in the regulator conversion efficiency.